Royal Society Publishing

The Measurement of Optical Radiation Pressure in Dispersive Media

R. V. Jones, B. Leslie


The paper describes the details of a repetition of the Jones-Richards experiment (1954) to compare the recoil of a mirror due to the radiation pressure of light striking it in an optically dense medium with the recoil of the same mirror from the same light in air. A more than tenfold improvement in precision has been possible through the development of the laser and of multilayer reflectors of high reflectivity and low absorption. The new experiment confirms, to a precision of about 0.05%, that the momentum associated with electromagnetic radiation increases directly with the refractive index of the medium into which it passes, discriminating substantially in favour of the phase velocity ratio and against the group velocity ratio. The experiment also shows that the magnitude of recoil of a mirror in oblique incidence does not vary, within the foregoing precision, when the plane of polarization is changed from perpendicular to parallel to the plane of incidence.